1. Field of the Invention
The present invention relates generally to ice making equipment and more particularly is directed to ice level sensors and controls for commercial volume flake-ice makers.
2. State of the Prior Art
Commercial type ice makers typically consist of an ice making head usually of cylindrical configuration in which a water filled container or trough has at least one refrigerated wall cooled by a flow of refrigerant gas, and a motor driven scraper which continuously breaks up ice forming on the refrigerated surface into ice flakes. The ice flakes are harvested from the surface of the water by mechanical paddles or equivalent means, and are discharged through one or more ice chutes into an underlying ice bin.
A problem in the past has been the excessive accumulation of ice in such an ice bin. Once the bin fills up with ice, new ice discharging from the head cannot drop through the chutes and the head becomes jammed with ice. The consequences can range from serious inconvenience, because the head must be cleared of ice, to severe mechanical damage to the ice making head including broken drive shafts, broken bearings and the like. It is therefore highly desirable to provide such ice makers with a reliable means for detecting excessive accumulations of ice in the collecting bin before the ice backs up in the ice making head.
Various devices and arrangements have been conceived for this deceptively simple purpose. All of them have been found to suffer from shortcomings either in terms of reliability, cost or complexity. One ice level detector available from the Howe Corporation as an accessory for their flake-ice makers consists of a small electric motor coupled through a friction clutch to a small fan blade arrangement. This assembly is mounted within the ice collecting bin at an ice level which is considered safe for operation of the ice making head. The fan blades are continuously driven by the electric motor. If ice builds up in the bin to an excessive level, it stops the rotating blades which disengage from the motor through the clutch and actuate a control relay arrangement which stops further operation of the ice making head while the ice level remains excessive in the bin. Once sufficient ice has been removed through normal consumption from the bin, the sensor paddles again are free to rotate and re-engaged to the continuously powered drive motor, re-enabling operation of the ice making head. This system is costly and inconvenient to install, and more complex than is desirable.